Lubricants for water-based drilling fluids

ABSTRACT

Embodiments are directed to a lubricant package for water based drilling fluids. The lubricant package includes water, a polyethylene glycol, and a lubricating agent. The lubricating agent includes triethanolamine, or a C 12 -C 14  alcohol ethoxylate, or a combination of triethanolamine and C 12 -C 14  alcohol ethoxylate. The weight ratio of the polyethylene glycol to the lubricating agent in the lubricant package is from 1:2 to 2:1. Embodiments are also directed to a water-based drilling fluid composition including an aqueous base fluid, one or more additives, and the lubricant package for water based drilling fluids.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 15/660,118 filed Jul. 26, 2017, which claimspriority to U.S. Provisional Patent Application Ser. Nos. 62/454,189filed Feb. 3, 2017, and 62/454,192 filed Feb. 3, 2017, all of which arehereby incorporated herein by reference.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to drillingfluids, lubricants for drilling fluids, and methods for using drillingfluids containing lubricants. More specifically, embodiments of thepresent disclosure relate to lubricants for water based drilling fluidsused for drilling oil wells and to water based drilling fluidcompositions comprising the lubricants.

BACKGROUND

Oil and gas hydrocarbons are naturally occurring in some subterraneanformations. During drilling operations, a drilling fluid, which may alsobe referred to as drilling mud, is circulated through the wellbore tocool the drill bit, to convey rock cuttings to the surface, or tosupport the wellbore against collapse of the wellbore and againstintrusion of fluids from the formation, among other purposes.Additionally, friction between the drill string and piping and thewellbore during the drilling operations generates heat and leads tofatigue and wear on the drilling equipment. The water or oil in thedrilling fluid may provide a lubricating functionality to reduce thecoefficient of friction and thereby friction between the drillingequipment and wellbore.

However, there is an ongoing need for drilling fluids and drilling fluidlubricating additives, and specifically water-based drilling fluids andlubricating additives, which provide improved lubrication between thedrilling equipment and wellbore during drilling operations.

SUMMARY

Embodiments of the present disclosure are directed to lubricant packagesfor water-based drilling fluids and associated drilling fluidcompositions comprising the lubricant package.

According to one or more embodiments, a lubricant package for waterbased drilling fluids includes water, a polyethylene glycol, and alubricating agent. The lubricating agent includes triethanolamine, or aC₁₂-C₁₄ alcohol ethoxylate, or a combination of triethanolamine andC₁₂-C₁₄ alcohol ethoxylate. Further, the weight ratio of thepolyethylene glycol to the lubricating agent in the lubricant package isfrom 1:2 to 2:1.

According to another aspect, a water-based drilling fluid compositionincludes an aqueous base fluid, one or more additives, and a lubricantpackage. The additives are chosen from an emulsifier, a weightingmaterial, a fluid-loss control additive, a viscosifier, and an alkalicompound. The lubricant package includes water, a polyethylene glycol,and a lubricating agent. The lubricating agent includes triethanolamine,or a C₁₂-C₁₄ alcohol ethoxylate, or a combination of triethanolamine andC₁₂-C₁₄ alcohol ethoxylate. Further, the weight ratio of thepolyethylene glycol to the lubricating agent in the lubricant package isfrom 1:2 to 2:1.

Additional features and advantages of the described embodiments will beset forth in the detailed description which follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the described embodiments, including thedetailed description which follows and the claims.

DETAILED DESCRIPTION

Drill strings for drilling subterranean wells include a drill bit anddrill collars to weight the drill bit. To drill a subterranean well thedrill string is inserted into a predrilled hole and is rotated to causethe drill bit to cut into the rock at the bottom of the hole. Thedrilling operation produces rock fragments. To remove the rock fragmentsfrom the bottom of the wellbore, a drilling fluid or a drilling fluidcomposition is pumped down through the drill string to the drill bit.Common categories of drilling fluids include drilling muds, packerfluids, drill-in fluids, and completion fluids. Generically, drillingfluids serve a number of functions, and with specific types of drillingfluids may specialize in a particular function or functions. Thedrilling fluid cools the drill bit, provides lubrication, and lifts therock fragments known as cuttings away from the drill bit. The drillingfluid carries the cuttings upwards as the drilling fluid is recirculatedback to the surface. At the surface, the cuttings are removed from thedrilling fluid through a secondary operation, and the drilling fluid isrecirculated back down the drill string to the bottom of the wellborefor collection of further cuttings.

Embodiments of the present disclosure are directed to lubricant packagesfor water-based drilling fluids and additionally to water-based drillingfluid compositions incorporating the lubricant package. The lubricantpackage is a combination of water, a polyethylene glycol, and alubricating agent. The lubricating agent may comprise triethanolamine, aC₁₂-C₁₄ alcohol ethoxylate, or a combination of triethanolamine and aC₁₂-C₁₄ alcohol ethoxylate. The weight ratio of the polyethylene glycolto the lubricating agent in the lubricant package is from 1:2 to 2:1.

The lubricant package includes water. In one or more embodiments, thelubricant package comprises 70 weight percent (wt. %) to 98 wt. % water.In various embodiments, the lubricant package comprises 70 wt. % to 95wt. % water, 75 wt. % to 98 wt. % water, 75 w. t % to 95 wt. % water, 80wt. % to 98 wt. % water, 80 wt. % to 95 wt. % water, 85 wt. % to 98 wt.% water, or 85 wt. % to 95 wt. % water.

The lubricant package includes polyethylene glycol. The polyethyleneglycol provides a lubrication and friction reducing functionality aswell as a freezing point depression functionality. Specifically,addition of polyethylene glycol to a water-based drilling fluid as acomponent of the lubricant package results in the coefficient offriction of the lubricant package independent of the remainingcomponents of the lubricant package. Additionally, the polyethyleneglycol reduces the freezing point of the lubricant package as well asthe entire water-based drilling fluid when included in the disclosedembodiments of a water-based drilling fluid.

In various embodiments, the polyethylene glycol includes polyethyleneglycols having a distribution of molecular weights. In one or moreembodiments, the polyethylene glycol comprises an average molecularweight of 250 to 700 grams per mole (g/mol). The polyethylene glycol mayalso comprise an average molecular weight of 500 to 700 g/mol, 525 to700 g/mol, 525 to 675 g/mol, 525 to 650 g/mol, 525 to 625 g/mol, 525 to600 g/mol, 550 to 700 g/mol, 550 to 675 g/mol, 550 to 650 g/mol, 550 to625 g/mol, 550 to 600 g/mol, 575 to 700 g/mol, 575 to 675 g/mol, 575 to650 g/mol, 575 to 625 g/mol, 575 to 600 g/mol, 590 to 610 g/mol, orapproximately 600 g/mol. In further embodiments, the polyethylene glycolcomprises an average molecular weight of 250 to 350 g/mol, 250 to 325g/mol, 250 to 300 g/mol, 275 to 350 g/mol, 275 to 325 g/mol, 275 to 300g/mol, 290 to 310 g/mol, or approximately 300 g/mol.

In one or more embodiments, the polyethylene glycol is a polyethyleneglycol having a freezing point from 12° C. to 17° C.

In one or more embodiments, the polyethylene glycol is a polyethyleneglycol having a flash point greater than 220° C. An elevated flash pointof the polyethylene glycol allows the resulting drilling fluid to beutilized in high temperature and pressure conditions.

In one or more embodiments, the lubricant package includestriethanolamine. Triethanolamine has the formula N(CH₂CH₂OH)₃. Thetriethanolamine may provide an alkaline buffer functionality to thedrilling fluid.

In one or more embodiments, the lubricant package comprises a C₁₂-C₁₄alcohol ethoxylate. The C₁₂-C₁₄ alcohol ethoxylate may have Formula (I):R(OCH₂CH₂)_(n)OH  Formula (I)In Formula (I), R is a saturated or unsaturated, linear or branchedhydrocarbyl group having from 8 to 18 carbon atoms. In embodiments, R isa saturated or unsaturated, linear or branched hydrocarbyl group having13 carbon atoms. In embodiments, R is —(CH₂)_(m)(CH₃)CHCH₃ where m isfrom 9 to 11. In some embodiments, m is 9, 10, or 11. Further, inembodiments, n is from 3 to 13 including 3, 4, 5, 6, 7, 8, 9, 10, 11,12, and 13 individually.

In some embodiments, the alcohol ethoxylate compound includes compoundshaving the chemical formula C₁₃H₂₇—(OCH₂CH₂)₈—OH. In one or moreembodiments, owing to the reactions by which alcohol ethoxylates areprepared, the alcohol ethoxylate comprising the compound of the chemicalformula C₁₃H₂₇—(OCH₂CH₂)₈—OH may include small amounts, for example lessthan 5 wt. %, less than 1 wt. %, less than 0.1 wt. %, or less than 0.01wt. %, of one or more other alcohol ethoxylates having the formulaR—(OCH₂CH₂)_(n)—OH in which “n” is an integer greater than or less than8, in a range of 3 to 13. In embodiments, the alcohol ethoxylate is acondensate of synthetic branched isotridecyl alcohol with eight moles ofethylene oxide. The alcohol ethoxylate may have the chemical formulaCH₃CH(CH₃)(CH₂)₁₀—(OCH₂CH₂)₈—OH.

In one or more embodiments, the alcohol ethoxylate may have a hydroxylvalue of 98 to 104 mg KOH/g. The hydroxyl value may be measured inaccordance with SKIM/QAD-SOP-209, which is incorporated herein byreference in its entirety.

In one or more embodiments, the alcohol ethoxylate may have ahydrophilic-lipophilic balance (HLB) of 8 to 16. The HLB may be measuredaccording to a standard technique, such as Griffin's method which statesHLB=20×M_(h)/M where M_(h) is the molecular mass of the hydrophilicportion of the molecule and M is the molecular mass of the wholemolecule. The resulting HLB value gives a result on a scale of from 0 to20 in which a value of 0 indicates to a completelyhydrophobic/lipophilic molecule and a value of 20 corresponds to acompletely hydrophilic/lipophobic molecule. Generally, a molecule havingan HLB of less than 10 is lipid-soluble (and thus water-insoluble) and amolecule having an HLB of greater than 10 is water-soluble (and thuslipid-insoluble). In various embodiments, the alcohol ethoxylate mayhave a hydrophilic-lipophilic balance of 9 to 15, 10 to 14.5, 11 to 14,12 to 13.5, 12.5 to 13 or approximately 12.75.

The lubricant package comprises a combination of water, the polyethyleneglycol, and the lubricating agent. The lubricating agent may comprisetriethanolamine, or a C₁₂-C₁₄ alcohol ethoxylate, or triethanolamine anda C₁₂-C₁₄ alcohol ethoxylate. The individual components of the lubricantpackage may be formulated in various ratios to accentuate variousproperties. In one or more embodiments, the weight ratio of thepolyethylene glycol to the lubricating agent in the lubricant package isfrom 1:2 to 2:1. In various embodiments, the weight ratio of thepolyethylene glycol to the lubricating agent in the lubricant package is5:9 to 9:5, 4:7 to 7:4, 3:5 to 5:3, or 2:3 to 3:2. Further, inembodiments, the weight ratio of the alcohol ethoxylate to thetriethanolamine in the lubricating agent is from 0:1 to 1:0, 10:1 to1:10, 5:1 to 1:5, 3:1 to 1:3, 2:1 to 1:2, or approximately 1:1.

The lubricant package increases lubricity and decreases friction betweenthe drill string and the wellbore during drilling operations. Areduction in the coefficient of friction of the lubricant package, andsimilarly a water-based drilling fluid containing the lubricant package,provides a reduction in friction experienced between the drill stringand the wellbore. In embodiments, the lubricant package has acoefficient of friction less than 20. In various further embodiments,the lubricant package has a coefficient of friction less than 19, lessthan 18, less than 17, less than 16, less than 15, or less than 14. Thecoefficient of friction may be measured in accordance with a standardlubricity coefficient test. Specifically, a lubricity testing device ascommonly used by those in the drilling fluid industry may be utilized,for example, a lubricity tester from OFI Testing Equipment, Inc (OFITE),Houston, Tex. In testing, the lubricant package is positioned between ahardened steel block and rotating ring. A 150 inch-pounds (in-lb) offorce is applied between the hardened steel block and rotating ringwhile the rotating ring spins at 60 rotations per minute (RPM). The 150in-lb of force is equivalent to 5,000 to 10,000 PSI pressure on thelubricant package. The lubricity testing device then provides a valuefor the coefficient of friction for the lubricant package based oninternal calculations of the lubricity testing device.

The lubricant package may be added to a water-based drilling fluid togenerate a water-based drilling fluid composition which includesembodiments of the lubricant package. An example water-based drillingfluid composition incorporating the lubricant package comprises anaqueous base fluid, one or more additives including emulsifiers,weighting material, fluid-loss control additives, viscosifiers, oralkali compounds, and a lubricant package as previously described,including polyethylene glycol and one or more of triethanolamine and aC₁₂-C₁₄ alcohol ethoxylate.

In one or more embodiments of the aqueous base fluid may include wateror a combination of oil and water. An aqueous base fluid may be anysuitable fluid such as water or a solution containing both water and oneor more organic or inorganic compounds dissolved in the water orotherwise completely miscible with the water. The water in the aqueousbase fluid may include one or more of fresh water, well water, filteredwater, distilled water, sea water, salt water, produced water, formationbrine, other types of water, or combinations of waters. The water-baseddrilling fluid compositions comprising oil in the aqueous base fluid mayhave a natural oil, a synthetic oil, or a combination thereof.

The water-based drilling fluid composition may have an amount of theaqueous base fluid sufficient to allow the water-based drilling fluidcomposition to be circulated to the drill bit at the bottom of awellbore and back to the surface. In embodiments, the water-baseddrilling fluid composition may include from 20 wt. % to 99 wt. % basefluid based on the total weight of the water-based drilling fluidcomposition. For example, the water-based drilling fluid composition mayhave from 20 wt. % to 80 wt. %, from 20 wt. % to 70 wt. %, from 20 wt. %to 60 wt. %, from 20 wt. % to 50 wt. %, from 20 wt. % to 40 wt. %, from23 wt. % to 99 wt. %, from 23 wt. % to 80 wt. %, from 23 wt. % to 70 wt.%, from 23 wt. % to 60 wt. %, from 23 wt. % to 50 wt. %, from 23 wt. %to 40 wt. %, from 24 wt. % to 99 wt. %, from 24 wt. % to 80 wt. %, from24 wt. % to 70 wt. %, from 24 wt. % to 60 wt. %, from 24 wt. % to 50 wt.%, from 24 wt. % to 40 wt. %, from 25 wt. % to 99 wt. %, from 25 wt. %to 80 wt. %, from 25 wt. % to 70 wt. %, from 25 wt. % to 60 wt. %, from25 wt. % to 50 wt. %, or from 25 wt. % to 40 wt. % aqueous base fluidbased on the total weight of the water-based drilling fluid composition.Said another way, the drilling fluids may include from 5 pounds perbarrel (lb/bbl) to 850 lb/bbl, 25 lb/bbl to 750 lb/bbl, 50 lb/bbl to 600lb/bbl, or 75 lb/bbl to 350 lb/bbl of base fluid.

In embodiments, the water-based drilling fluid composition may include aweighting material. In some embodiments, the weighting material may be aparticulate solid having a specific gravity (SG) sufficient to increasethe density of the drilling fluid composition by a certain amountwithout adding excessive weighting material such that the drilling fluidcomposition cannot be circulated through the wellbore. The weightingmaterial may have a specific gravity (SG) of from 2 grams per cubiccentimeter (g/cm³) to 6 g/cm³. Examples of weighting materials include,but are not limited to, barite (minimum SG of 4.20 g/cm³), hematite(minimum SG of 5.05 g/cm³), calcium carbonate (minimum SG of 2.7-2.8g/cm³), siderite (minimum SG of 3.8 g/cm³), ilmenite (minimum SG of 4.6g/cm³), other weighting materials, or any combination of these weightingmaterials. Some example drilling fluid compositions may include bariteas the solid.

The water-based drilling fluid composition may include an amount ofweighting material sufficient to increase the density of the drillingfluid composition to allow the drilling fluid composition to support thewellbore and prevent fluids in downhole formations from flowing into thewellbore. In embodiments, the water-based drilling fluid composition mayinclude from 1 wt. % to 80 wt. % weighting material based on the totalweight of the water-based drilling fluid composition. In someembodiments, the water-based drilling fluid composition may include from1 wt. % to 75 wt. %, from 1 wt. % to 74 wt. %, from 1 wt. % to 73 wt. %,from 1 wt. % to 70 wt. %, from 1 wt. % to 60 wt. %, from 20 wt. % to 80wt. %, from 20 wt. % to 75 wt. %, from 20 wt. % to 74 wt. %, from 20 wt.% to 73 wt. %, from 20 wt. % to 70 wt. %, from 20 wt. % to 60 wt. %,from 50 wt. % to 80 wt. %, from 50 wt. % to 75 wt. %, from 50 wt. % to74 wt. %, from 50 wt. % to 73 wt. %, from 50 wt. % to 70 wt. %, from 50wt. % to 60 wt. %, from 60 wt. % to 80 wt. %, or from 60 wt. % to 75 wt.% weighting material, based on the total weight of the water-baseddrilling fluid composition. Said another way, the drilling fluids mayinclude from 5 ppb to 850 ppb, 50 ppb to 750 ppb, 150 ppb to 700 ppb, or200 ppb to 650 ppb of weighting material.

The drilling fluid composition may have a density of from 60 pounds ofmass per cubic foot (lbm/ft³) to 155 lbm/ft³, from 60 lbm/ft³ to 130lbm/ft³, from 60 lbm/ft³ to 120 lbm/ft³, from 70 lbm/ft³ to 140 lbm/ft³,from 70 lbm/ft³ to 125 lbm/ft³, from 70 lbm/ft³ to 110 lbm/ft³, from 80lbm/ft³ to 120 lbm/ft³, from 80 lbm/ft³ to 110 lbm/ft³, or from 80lbm/ft³ to 100 lbm/ft³, where 1 lbm/ft³ is approximately 16.02 kilogramsper cubic meter (kg/m³). In some embodiments, the drilling fluidcomposition may have a density that is approximately equal to 90 lbm/ft³(1,442 kg/m³), alternatively commonly referenced as 90 pcf.

The water-based drilling fluid composition may include at least onesolid-phase component. Examples of solid-phase components in thewater-based drilling fluid compositions may include, but are not limitedto, the weighting materials, starch, soda ash, bentonite, lime, sodiumsulfite, other solid-phase component, or combinations of thesesolid-phase components. All of the solid-phase components together makeup a total solids content of the water-based drilling fluid composition.In some embodiments, the water-based drilling fluid composition may havea total solids content of equal to or greater than 50 wt. % based on thetotal weight of the water-based drilling fluid composition.Alternatively, in other embodiments, the water-based drilling fluidcomposition may have a solids content of equal to or greater than 60 wt.% based on the total weight of the water-based drilling fluidcomposition.

The water-based drilling fluid compositions may optionally include oneor a plurality of additives to enhance the properties andcharacteristics of the water-based drilling fluid composition. Examplesof the additives include, but are not limited to, emulsifiers,fluid-loss control additives, viscosifiers (viscosity control agents),alkali compounds, or combinations of these. The water-based drillingfluid composition may also optionally include pH buffers, electrolytes,glycols, glycerols, dispersion aids, corrosion inhibitors, defoamers,and other additives or combinations of additives. In embodiments, thewater-based drilling fluid composition may optionally include aviscosifier to impart non-Newtonian fluid rheology to the water-baseddrilling fluid composition to facilitate lifting and conveying rockcuttings to the surface of the wellbore. Examples of viscosifiers mayinclude, but are not limited to, xanthan gum polymer (XC polymer),bentonite, polyacrylamide, polyanionic cellulose, or combinations ofthese viscosifiers. In some embodiments, the water-based drilling fluidcomposition may optionally include xanthan gum polymer, which is apolysaccharide secreted by the bacteria Xanthomonas Campestris (XC). Anexample water-based drilling fluid composition may optionally includefrom 0.03 to 1 lb/bbl of a xanthan gum polymer. Unless otherwise stated,the weight percent of an additive in the water-based drilling fluidcomposition is based on the total weight of the water-based drillingfluid composition. In some embodiments, the water-based drilling fluidcomposition may optionally include from 0.03 to 1 lb/bbl bentonite. Thewater-based drilling fluid composition may optionally include othersuitable viscosifiers without deviating from the scope of the presentsubject matter.

The water-based drilling fluid composition may optionally include atleast one pH adjuster. In embodiments, the water-based drilling fluidcomposition may optionally include at least one alkali compound.Examples of alkali compounds may include, but are not limited to, lime(calcium hydroxide or calcium oxide), soda ash (sodium carbonate),sodium hydroxide, potassium hydroxide, other strong base, orcombinations of these alkali compounds. The alkali compounds may reactwith gases, such as CO₂ or H₂S for example, encountered by the drillingfluid composition during drilling operations to prevent the gases fromhydrolyzing components of the water-based drilling fluid composition.Some example water-based drilling fluid compositions may optionallyinclude from 0.33 to 10 lb/bbl of soda ash. Other example water-baseddrilling fluid compositions may optionally include from 0.3 to 10 lb/bblof lime. In embodiments, the water-based drilling fluid composition mayhave a pH of from 7 to 12, from 7 to 10.5, from 7 to 10, from 9 to 12,from 9 to 10.5, from 9 to 10, from 9.5 to 12, from 9.5 to 10.5, from 9.5to 10, from 7.5 to 9, from 7.5 to 9.5, or from 10 to 12. In someembodiments, the water-based drilling fluid composition may have a pH offrom 9 to 10.5.

The water-based drilling fluid composition may optionally include atleast one emulsifier. In one or more embodiments, the drilling fluidcomposition may include from 7 ppb to 25 ppb of emulsifier, from 8 ppbto 20 ppb of emulsifier, or from 9 ppb to 15 ppb of emulsifier. In oneor more embodiments, the emulsifier may be an invert emulsifier andoil-wetting agent for synthetic based drilling fluid systems such as LESUPERMUL™ commercially available from Halliburton Energy Services, Inc.

The water-based drilling fluid composition may optionally include atleast one fluid-loss control additive. The drilling fluid compositionmay include from 1 ppb to 10 ppb of fluid-loss control additive, from 1ppb to 5 ppb of fluid-loss control additive, from 1.5 ppb to 8 ppb offluid-loss control additive, or from 1.5 ppb to 2.5 ppb of fluid-losscontrol additive. In one or more embodiments, the fluid-loss additivemay be a polyaninoic cellulose. The fluid-loss additive may additionallyor alternatively be a modified starch, a xanthan gum, or2-acrylamido-2-methyl propane sulfonic acid (AMPS).

In embodiments, the water-based drilling fluid composition also providesa cooling and lubrication functionality for cooling and lubrication ofthe bit and drill string utilized in boring operations. Embodiments ofthe lubricant package and water-based drilling fluids comprising thelubricant package are formulated to provide improved lubricationfunctionality for lubrication of the bit and drill string utilized inboring operations. The lubricant package imparts enhanced lubricity tothe water-based drilling fluid composition thereby providing increasedlubrication and reduced friction between the drill string, pipe, andwellbore during drilling operations. The synergistic effect of both thepolyethylene glycol and triethanolamine or the polyethylene glycol andalcohol ethoxylate imparts the enhanced lubrication and frictionreduction. Without wishing to be bound by theory it is believed there isa hydrophilic interaction between the head groups of the polyethyleneglycol-triethaniolamine and polyethylene glycol-alcohol ethoxylate toimpart the enhanced lubrication and friction reduction.

EXAMPLES

The following examples illustrate one or more additional features of thepresent disclosure. It should be understood that these examples are notintended to limit the scope of the disclosure or the appended claims inany manner.

In the following examples, lubricating fluids with varying amounts ofwater, polyethylene glycol, and lubricating agent were prepared. Thepolyethylene glycol, the lubricating agent, and both the freezing pointdepressant and lubricating agent were tested in combination with water.The testing included combinations of water, polyethylene glycol, andlubricating agent encompassed by embodiments of the lubricant packagepreviously described. The physical characteristics of the polyethyleneglycols used in the lubricating fluids are provided in Tables 1 and 2.The physical characteristics of the alcohol ethoxylate are provided inTable 3. The coefficients of friction of the various tested lubricatingfluids are described in Table 4.

Example 1 (Comparative) Water and Polyethylene Glycol (MW 300)

A lubricating fluid formulated from 250 milliliters (mL) of water and 15grams (g) of polyethylene glycol with a molecular weight of 300 wasprepared as an Example 1 for comparison with embodiments of thelubricant package. The constituents of Example 1 were simultaneouslymixed for 5 minutes to prepare Example 1. Details of the physicalproperties of the polyethylene glycol (MW 300) are provided in Table 1.

TABLE 1 Physical Properties of Polyethylene Glycol (MW 300) PropertyTest Method Value Molecular Weight 300 Appearance at 25° C.SKIMS/QAD-SOP-168 Clear Viscous Liquid Hydroxyl No. (mgKOH/g)SKIMS/QAD-SOP-209 356.0-394.0 Water (%), Max. ASTM-E-203 0.5 Color(APHA), at 25° C., ASTM-D-1209 40 Max. pH at 25° C. for 5 wt. %ASTM-D-4252 4.5-7.5 in Aqueous Solution Density at 25° C., g/ml1.12-1.13 Freezing Point Range (° C.) 5-9 Flash Point (° C.) Over 150Ash Content %, Max. 0.1

Example 2 (Comparative) Water and Polyethylene Glycol (MW 600)

A lubricating fluid formulated from 250 mL of water and 15 g ofpolyethylene glycol with a molecular weight of 600 was prepared as anExample 2 for comparison with embodiments of the lubricant package. Theconstituents of Example 2 were simultaneously mixed for 5 minutes toprepare Example 2. Details of the physical properties of thepolyethylene glycol (MW 600) are provided in Table 2.

TABLE 2 Physical Properties of Polyethylene Glycol (MW 600) PropertyTest Method Value Molecular Weight 600 Appearance at 25° C.SKIMS/QAD-SOP-168 Clear Viscous Liquid Hydroxyl No. (mgKOH/g)SKIMS/QAD-SOP-209 178-197 Water (%), Max. ASTM-E-203 0.5 Color (APHA),at 25° C., ASTM-D-1209 40 Max. pH at 25° C. for 5 wt. % in ASTM-D-42524.5-7.5 Aqueous Solution Density at 25° C., g/ml — 1.1258 Freezing PointRange (° C.) — 12-17 Flash Point (° C.) — Over 220 Ash Content %, Max. —0

Example 3 (Comparative) Water and Triethanolamine

A lubricating fluid formulated from 250 mL of water and 15 g oftriethanolamine was prepared as an Example 3 for comparison withembodiments of the lubricant package. The constituents of Example 3 weresimultaneously mixed for 5 minutes to prepare Example 3. Details of thephysical properties of the triethanolamine are provided in Table 3.

TABLE 3 Physical Properties of Triethanolamine Property Test MethodValue Appearance at 30° C. SKIMS/QAD-SOP-168 Clear Liquid Water (%),Max. ASTM-E-203 0.2 Freezing Point (° C.) — 21 Flash Point (° C.) — Over190 Boiling Point (° C.) — 360

Example 4 (Comparative) Water and Alcohol Ethoxylate

A lubricating fluid formulated from 250 mL of water and 15 g of analcohol ethoxylate was formulated as an Example 4 for comparison withembodiments of the lubricant package. The constituents of Example 4 weresimultaneously mixed for 5 minutes to prepare Example 4. Details of thephysical properties of the alcohol ethoxylate are provided in Table 4.Specifically, the alcohol ethoxylate was a C₁₃ alcohol ethoxylate andmore specifically had the chemical formulaCH₃CH(CH₃)(CH₂)₁₀—(OCH₂CH₂)₈—OH.

TABLE 4 Physical Properties of Alcohol Ethoxylate Property Test MethodValue Appearance at 25° C. SKIMS/QAD-SOP-168 Liquid Hydroxyl No.(mgKOH/g) SKIMS/QAD-SOP-209 98-104 Water (%), Max. ASTM-E-203 0.5 pH at25° C. for 5 wt. % in ASTM-D-4252 5-7 Aqueous Solution Cloud point (5g + 25 g of ASTM-D-2024 78 -83 25% w/w butyl diglycol (BDG) in DIwater), ° C. HLB Calculated 12.75

Example 5 Water, Triethanolamine, and Polyethylene Glycol (MW 600)

A lubricant package in accordance with embodiments of this disclosureformulated from 250 mL of water, 15 g of triethanolamine, and 15 g ofpolyethylene glycol (MW 600) was prepared as an Example 5. Theconstituents of Example 5 were simultaneously mixed for 5 minutes toprepare Example 5.

Example 6 Water, Alcohol Ethoxylate, and Polyethylene Glycol (MW 600)

A lubricant package in accordance with embodiments of this disclosureformulated from 250 mL of water, 15 g of CH₃CH(CH₃)(CH₂)₁₀—(OCH₂CH₂)₈—OHalcohol ethoxylate, and 15 g of polyethylene glycol (MW 600) wasprepared as an Example 6. The constituents of Example 6 weresimultaneously mixed for 5 minutes to prepare Example 6.

The lubricating fluids of Examples 1-4 (Comparative Examples) andExamples 5-6 were evaluated to determine the coefficient of friction foreach sample. A lubricity testing device as commonly used by those in thedrilling fluid industry was utilized to determine the coefficient offriction for each sample. Specifically, a lubricity tester from OFITesting Equipment, Inc (OFITE), Houston, Tex. was utilized. In testing,each lubricating fluids of Comparative Examples 1-4 and InventiveExamples 1-2 were individually positioned between a hardened steel blockand rotating ring. A force of 150 inch-pounds (in-lb) was appliedbetween the hardened steel block and the rotating ring while therotating ring spun at 60 rotations per minute (RPM). The lubricitytesting device recorded the force required to spin the rotating ring andbased on internal calculations the lubricity testing device provided acoefficient of friction value for each of Examples 1-4 (Comparative) andExamples 5-6. The results of these measurements for the lubricatingfluids of Examples 1-4 (Comparative) and Examples 5-6 are provided inTable 5. Table 4 also includes a calculated reduction in the coefficientof friction compared to a pure water sample.

TABLE 5 Evaluation of the Properties of the Lubricating Fluids ofExamples 1-4 (Comparative) and Examples 5-6 Coefficient Reduction inLubricating of Friction Coefficient Fluid Formulation (Torque) ofFriction Example 1 250 mL Water 0.354 — (Comparative) 250 mL Water +0.306 13.56% 15 g Polyethylene Glycol (MW 300) Example 2 250 mL Water0.354 — (Comparative) 250 mL Water + 0.302 14.69% 15 g PolyethyleneGlycol (MW 600) Example 3 250 mL Water 0.352 — (Comparative) 250 mLWater + 0.335  4.83% 15 g Triethanolamine Example 4 250 mL Water 0.346 —(Comparative) 250 mL Water + 0.224 35.26% 15 g C₁₃ Alcohol EthoxylateExample 5 250 mL Water 0.358 — 250 mLWater + 0.163 54.47% 15 gTriethanolamine + 15 g Polyethylene Glycol (MW 600) Example 6 250 mLWater 0.358 — 250 mL Water + 0.132 63.13% 15 g C₁₃ Alcohol Ethoxylate +15 g Polyethylene Glycol (MW 600)

As shown in Table 5, the lubricant package of Example 5, which includedthe triethanolamine and polyethylene glycol, resulted in an over 54%reduction in the coefficient of friction compared to just the basewater. Similarly, the lubricant package of Example 6, which included theC₁₃ alcohol ethoxylate and polyethylene glycol, resulted in an over 63%reduction in the coefficient of friction compared to just the basewater. The synergistic effect of the C₁₃ alcohol ethoxylate andpolyethylene glycol or triethanolamine and polyethylene glycol incombination in reducing the coefficient of friction compared to thecomponents of the lubricating fluid in isolation is evident.Specifically, the polyethylene glycol (MW 600) in isolation only had a14.69% reduction in the coefficient of friction compared to just thebase water, the triethanolamine in isolation only had a 4.83% reductionin the coefficient of friction compared to just the base water, and theC₁₃ alcohol ethoxylate in isolation only had a 35.26% reduction in thecoefficient of friction compared to just the base water. An 18.81%reduction when the polyethylene glycol (600 MW) and triethanolamine areused in combination would be expected based on the combination of a14.69% and 4.83% reduction; however, the much greater 54.47% reductionis noted. Similarly, a 44.77% reduction when the polyethylene glycol(600 MW) and C₁₃ alcohol ethoxylate are used in combination would beexpected based on the combination of a 14.69% and 35.26% reduction;however, the much greater 63.13% reduction is noted.

It should be understood that the various aspects of the method of makingBTX compounds including benzene, toluene, and xylene, and the compositezeolite catalyst utilized in the same are described and such aspects maybe utilized in conjunction with various other aspects.

In a first aspect, the disclosure provides a lubricant package for waterbased drilling fluids. The lubricant package includes water, apolyethylene glycol, and a lubricating agent. The lubricating agentcomprises triethanolamine, or a C₁₂-C₁₄ alcohol ethoxylate, or acombination of triethanolamine and C₁₂-C₁₄ alcohol ethoxylate. Theweight ratio of the polyethylene glycol to the lubricating agent in thelubricant package is from 1:2 to 2:1.

In a second aspect, the disclosure provides the lubricant package of thefirst aspect, in which the polyethylene glycol comprises polyethyleneglycols having a distribution of molecular weights and an averagemolecular weight of 500 to 700 grams/mole.

In a third aspect, the disclosure provides the lubricant package of thefirst aspect, in which the polyethylene glycol comprises polyethyleneglycols having a distribution of molecular weights and with an averagemolecular weight of 590 to 610 grams/mole.

In a fourth aspect, the disclosure provides the lubricant package of thefirst aspect, in which the polyethylene glycol comprises polyethyleneglycols having a distribution of molecular weights and an averagemolecular weight of 250 to 350 grams/mole.

In a fifth aspect, the disclosure provides the lubricant package of anyof the first through fourth aspects, in which the polyethylene glycol isa polyethylene glycol having a freezing point from 12° C. to 17° C.

In a sixth aspect, the disclosure provides the lubricant package of anyof the first through fifth aspects, in which the polyethylene glycol isa polyethylene glycol having a flash point greater than 220° C.

In a seventh aspect, the disclosure provides the lubricant package ofany of the first through sixth aspects, in which the lubricating agentcomprises triethanolamine or a combination of triethanolamine andC₁₂-C₁₄ alcohol ethoxylate.

In an eighth aspect, the disclosure provides the lubricant package ofany of the first through sixth aspects, in which the lubricating agentcomprises C₁₂-C₁₄ alcohol ethoxylate or a combination of triethanolamineand C₁₂-C₁₄ alcohol ethoxylate.

In a ninth aspect, the disclosure provides the lubricant package of anyof the first through eighth aspects, in which the C₁₂-C₁₄ alcoholethoxylate is a C₁₃ alcohol ethoxylate.

In a tenth aspect, the disclosure provides the lubricant package of anyof the first through ninth aspects, in which the alcohol ethoxylate is acondensate of synthetic branched isotridecyl alcohol with three tothirteen moles of ethylene oxide.

In an eleventh aspect, the disclosure provides the lubricant package ofany of the first through tenth aspects, in which the alcohol ethoxylateis a condensate of synthetic branched isotridecyl alcohol with eightmoles of ethylene oxide.

In a twelfth aspect, the disclosure provides the lubricant package ofany of the first through eleventh aspects, in which the alcoholethoxylate has the chemical formula CH₃CH(CH₃)(CH₂)₁₀—(OCH₂CH₂)₈—OH.

In a thirteenth aspect, the disclosure provides the lubricant package ofany of the first through twelfth aspects, in which the lubricant packagecomprises a C₁₂-C₁₄ alcohol ethoxylate having a hydroxyl value of 98-104mg KOH/g measured according to SKIMS/QAD-SOP-209.

In a fourteenth aspect, the disclosure provides the lubricant package ofany of the first through thirteenth aspects, in which the lubricantpackage comprises a C₁₂-C₁₄ alcohol ethoxylate having ahydrophilic-lipophilic balance of 8 to 16.

In a fifteenth aspect, the disclosure provides the lubricant package ofany of the first through thirteenth aspects, in which the lubricantpackage comrpises a C₁₂-C₁₄ alcohol ethoxylate having ahydrophilic-lipophilic balance of 12.5 to 13.0.

In a sixteenth aspect, the disclosure provides the lubricant package ofany of the first through fifteenth aspects, in which the weight ratio ofthe polyethylene glycol to the lubricating agent in the lubricantpackage is from 2:3 to 3:2.

In a seventeenth aspect, the disclosure provides the lubricant packageof any of the first through sixteenth aspects, in which the lubricantpackage comprises 70 wt. % to 98 wt. % water.

In an eighteenth aspect, the disclosure provides the lubricant packageof any of the first through seventeenth aspects, in which the lubricantpackage comprises 85 wt. % to 95 wt. % water.

In a nineteenth aspect, the disclosure provides the lubricant package ofany of the first through eighteenth aspects, in which the lubricantpackage has a coefficient of friction less than 20.

In a twentieth aspect, the disclosure provides the lubricant package ofany of the first through eighteenth aspects, in which the lubricantpackage has a coefficient of friction less than 18.

In a twenty-first aspect, the disclosure provides the lubricant packageof any of the first through eighteenth aspects, in which the lubricantpackage has a coefficient of friction less than 14.

In a twenty-second aspect, the disclosure provides a water-baseddrilling fluid composition. The water-based drilling fluid compositioncomprises an aqueous base fluid, one or more additives chosen from aweighting material, a fluid-loss control additive, a viscosifier, and analkali compound, and a lubricant package. The lubricant packagecomprises water, a polyethylene glycol, a lubricating agent. Thelubricating agent comprises triethanolamine, or a C₁₂-C₁₄ alcoholethoxylate, or a combination of triethanolamine and C₁₂-C₁₄ alcoholethoxylate. The weight ratio of the polyethylene glycol to thelubricating agent is from 1:2 to 2:1.

In a twenty-third aspect, the disclosure provides the drilling fluid ofthe twenty-second aspect, in which the polyethylene glycol comprisespolyethylene glycols having a distribution of molecular weights and anaverage molecular weight of 500 to 700 grams/mole.

In a twenty-fourth aspect, the disclosure provides the drilling fluid ofthe twenty-second aspect, in which the polyethylene glycol comprisespolyethylene glycols having a distribution of molecular weights and withan average molecular weight of 590 to 610 grams/mole.

In a twenty-fifth aspect, the disclosure provides the drilling fluid ofthe twenty-second aspect, in which the polyethylene glycol comprisespolyethylene glycols having a distribution of molecular weights and anaverage molecular weight of 250 to 350 grams/mole.

In a twenty-sixth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through twenty-fifth aspects, in which thepolyethylene glycol is a polyethylene glycol having a freezing pointfrom 12° C. to 17° C.

In a twenty-seventh aspect, the disclosure provides the drilling fluidof any of the twenty-second through twenty-sixth aspects, in which thepolyethylene glycol is a polyethylene glycol having a flash pointgreater than 220° C.

In a twenty-eighth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through twenty-seventh aspects, in which thelubricating agent comprises triethanolamine or a combination oftriethanolamine and C₁₂-C₁₄ alcohol ethoxylate.

In a twenty-ninth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through twenty-seventh aspects, in which thelubricating agent comprises C₁₂-C₁₄ alcohol ethoxylate or a combinationof triethanolamine and C₁₂-C₁₄ alcohol ethoxylate.

In a thirtieth aspect, the disclosure provides the drilling fluid of anyof the twenty-second through twenty-ninth aspects, in which the C₁₂-C₁₄alcohol ethoxylate is a C₁₃ alcohol ethoxylate.

In a thirty-first aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirtieth aspects, in which the alcoholethoxylate is a condensate of synthetic branched isotridecyl alcoholwith three to thirteen moles of ethylene oxide.

In a thirty-second aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirty-first aspects, in which thealcohol ethoxylate is a condensate of synthetic branched isotridecylalcohol with eight moles of ethylene oxide.

In a thirty-third aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirty-second aspects, in which thealcohol ethoxylate has the chemical formulaCH₃CH(CH₃)(CH₂)₁₀—(OCH₂CH₂)₈—OH.

In a thirty-fourth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirty-third aspects, in which thedrilling fluid comprises a C₁₂-C₁₄ alcohol ethoxylate having a hydroxylvalue of 98-104 mg KOH/g measured according to SKIMS/QAD-SOP-209.

In a thirty-fifth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirty-fourth aspects, in which thedrilling fluid comprises a C₁₂-C₁₄ alcohol ethoxylate having ahydrophilic-lipophilic balance of 8 to 16.

In a thirty-sixth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirty-fifth aspects, in which thedrilling fluid comprises a C₁₂-C₁₄ alcohol ethoxylate having ahydrophilic-lipophilic balance of 12.5 to 13M.

In a thirty-seventh aspect, the disclosure provides the drilling fluidof any of the twenty-second through thirty-sixth aspects, in which theweight ratio of the polyethylene glycol to the lubricating agent in thelubricant package is from 2:3 to 3:2.

In a thirty-eighth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirty-seventh aspects, in which thelubricant package comprises 70 wt. % to 98 wt. % water.

In a thirty-ninth aspect, the disclosure provides the drilling fluid ofany of the twenty-second through thirty-eighth aspects, in which thelubricant package comprises 85 wt. % to 95 wt. % water.

In a fortieth aspect, the disclosure provides the drilling fluid of anyof the twenty-second through thirty-ninth aspects, in which thelubricant package has a coefficient of friction less than 20.

It should be understood that any two quantitative values assigned to aproperty may constitute a range of that property, and all combinationsof ranges formed from all stated quantitative values of a given propertyare contemplated in this disclosure.

Having described the subject matter of the present disclosure in detailand by reference to specific embodiments, it should be apparent to thoseskilled in the art that various modifications and variations can be madeto the described embodiments without departing from the spirit and scopeof the claimed subject matter. Thus it is intended that thespecification cover the modifications and variations of the variousdescribed embodiments.

What is claimed is:
 1. A lubricant package for water based drillingfluids, the lubricant package comprising: water; a polyethylene glycolhaving a general formula in accordance with H—(O—CH₂—CH₂)_(n)—OH with nrepresenting a distribution of integers to provide an average molecularweight of 250 to 700 grams/mole; and a lubricating agent comprisingtriethanolamine, or a C₁₂-C₁₄ alcohol ethoxylate, or a combination oftriethanolamine and C₁₂-C₁₄ alcohol ethoxylate, in which the weightratio of the polyethylene glycol to the lubricating agent in thelubricant package is from 1:2 to 2:1.
 2. The lubricant package of claim1, in which the polyethylene glycol comprises polyethylene glycolshaving a distribution of molecular weights and an average molecularweight of 500 to 700 grams/mole.
 3. The lubricant package of claim 1, inwhich the polyethylene glycol comprises polyethylene glycols having adistribution of molecular weights and an average molecular weight of 250to 350 grams/mole.
 4. The lubricant package of claim 1, in which thelubricating agent comprises triethanolamine or a combination oftriethanolamine and C₁₂-C₁₄ alcohol ethoxylate.
 5. The lubricant packageof claim 1, in which the lubricating agent comprises C₁₂-C₁₄ alcoholethoxylate or a combination of triethanolamine and C₁₂-C₁₄ alcoholethoxylate.
 6. The lubricant package of claim 1, in which the C₁₂-C₁₄alcohol ethoxylate is a C₁₃ alcohol ethoxylate.
 7. The lubricant packageof claim 1, in which the alcohol ethoxylate is a condensate of syntheticbranched isotridecyl alcohol with three to thirteen moles of ethyleneoxide.
 8. The lubricant package of claim 1, in which the alcoholethoxylate is a condensate of synthetic branched isotridecyl alcoholwith eight moles of ethylene oxide.
 9. The lubricant package of any ofclaim 1, in which the alcohol ethoxylate has the chemical formulaCH₃CH(CH₃)(CH₂)₁₀—(OCH₂CH₂)₈—OH.
 10. The lubricant package of claim 1,comprising a C₁₂-C₁₄ alcohol ethoxylate having a hydroxyl value of98-104 mg KOH/g measured according to SKIMS/QAD-SOP-209.
 11. Thelubricant package of claim 1, comprising a C₁₂-C₁₄ alcohol ethoxylatehaving a hydrophilic-lipophilic balance of 8 to
 16. 12. The lubricantpackage of claim 1, in which the weight ratio of the polyethylene glycolto the lubricating agent in the lubricant package is from 2:3 to 3:2.13. The lubricant package of claim 1, in which the lubricant packagecomprises 70 wt. % to 98 wt. % water.
 14. The lubricant package of claim1, in which the lubricant package has a coefficient of friction lessthan
 20. 15. A water-based drilling fluid composition comprising: anaqueous base fluid; one or more additives chosen from a weightingmaterial, a fluid-loss control additive, a viscosifier, and an alkalicompound; and a lubricant package comprising: water; a polyethyleneglycol having a general formula in accordance with H—(O—CH₂—CH₂)_(n)—OHwith n representing a distribution of integers to provide an averagemolecular weight of 250 to 700 grams/mole; and a lubricating agentcomprising triethanolamine, or a C₁₂-C₁₄ alcohol ethoxylate, or acombination of triethanolamine and C₁₂-C₁₄ alcohol ethoxylate, in whichthe weight ratio of the polyethylene glycol to the lubricating agent isfrom 1:2 to 2:1.
 16. The water-based drilling fluid composition of claim15, in which the polyethylene glycol comprises polyethylene glycolshaving a distribution of molecular weights and with an average molecularweight of 590 to 610 grams/mole.
 17. The water-based drilling fluidcomposition of claim 15, in which the lubricating agent comprisestriethanolamine or a combination of triethanolamine and C₁₂-C₁₄ alcoholethoxylate.
 18. The water-based drilling fluid composition of claim 15,in which the lubricating agent comprises C₁₂-C₁₄ alcohol ethoxylate or acombination of triethanolamine and C₁₂-C₁₄ alcohol ethoxylate.
 19. Thewater-based drilling fluid composition of claim 15, in which the alcoholethoxylate is a condensate of synthetic branched isotridecyl alcoholwith eight moles of ethylene oxide.
 20. The water-based drilling fluidcomposition of claim 15, in which the weight ratio of the polyethyleneglycol to the lubricating agent in the lubricant package is from 2:3 to3:2.